Re: Aikido and pregnancy
I am not an expert! And as time comes, you should consult with one.
We have a women trainee who kept practicing until a few days before the birth, twice, and she did not have problems. She did tell Sensei rather early and change her regime: almost no breakfalls at all, no contact to the stomach, and as the pregnancy progressed - much lower level of straining (= none).
Not sure this is the kind of things in which all are the same. I rather believe the opposite is true. Age, pregnancy type (high risk / twins / ...) and lots of other things, might decide things for you, at any stage.
I would comment that expecting matrimony not to affect your practice is not realistic. My twin girls are 1 year 4 months old and I am still more of guest then a constant practitioner at the dojo. Sickness, lack of sleep and many other reasons appear rather often and prevent me from going to train (and I am the father).